English · Daily Life
rule of thumb
/ruːl əv θʌm/
[/ruːl əv θʌm/]
rough practical guide
Intermediatephrase
Definition
A general principle based on experience and practice rather than exact measurement.
Example
As a rule of thumb, you should drink about two litres of water on a hot summer day.
As a rule of thumb, you should drink about two litres of water on a hot summer day.
Etymology
A 17th-century phrase referring to practical estimation, possibly using the thumb as a rough measure.
How & Where It’s Used
Common for offering an approximate, practical guideline.